Hi Everyone, first post on this wonderful forum.
I'm working at an animation where some 3D comps are rotating along a circular path (a kind of carousel let's say). The comps are auto-oriented towards the camera and inside each there is an adjustment layer with fast blur applied. The goal is to have the foreground comp to blur everything behind...and it's almost working...BUT, as aftereffects "reads" layers from top down, at some point the effect is broken (the background comp is blurring the frontmost one).
I rendered a simplified version to illustrate the problem:
Is there a way to overcome this issue? Am I doing it right at all?
Thanks in advance for any advice!
Its ultimately the adjustment layer of the item in the back that is having the effect on the one in the front as you surmised.
I don't have an elegant solution for all situations, but I do have a quick and dirty that can add a little more dynamics to the comp.
Assumption: the camera is facing directly down the Z axis and each subcomp is used exactly once.
Enable expressions on the blur value of each adjustment layer within your subcomps. Tie that value to the Z value of rotating item in the main comp. I imagine the expression will look like comp("maincompname").layer("sprite_antinecendio").transform.position*[modifier] If the negative Z axis is the foreground this modifier will be negative and very like a very small number (-.01 -.05). You could also link that modifier to an expression control to give you master control over the blur without having to edit each expression.
Blur can't go below zero so it will return all negative values as 0 blur. In doing so you will set the items that are in the back of the rotation to have zero blur thus not impacting your front element. This will also mean that the further forward the item is the stronger the blur on the background items (I'd consider a zoom blur over fast blur for this). If you wanted a binary on/off, then I guess use an if/then expression to set the blur to either the full value or zero.